The present disclosure relates to a vertical takeoff and landing (VTOL) rotary-wing aircraft, and more particularly to an external cargo hook system therefor.
Vertical takeoff and landing (VTOL) rotary-wing aircraft are unique in their ability to carry loads externally. External load operations provide a rapid procedure to load, transport, and unload cargo. Frequently, a sling or set of slings are used to attach the slung load to the aircraft for transportation. External load operations are particularly advantageous for situations where ground topography is not conducive to aircraft landing, or where rapid cargo loading and unloading is required.
Conventional external cargo hook systems locate a cargo hook within a lower belly portion of an aircraft airframe. The load on the conventional belly mounted cargo hook transfers the load on the hook system around the open cargo space of the aircraft cabin, and then into an upper portion of the aircraft airframe. Although effective, this indirect load path may parallelogram the frame in response to some flight loads and place undesirable stresses on the airframe. Other conventional cargo hook systems locate a frame structure within an upper portion of the aircraft cabin. Although this provides a more direct load path through the airframe, the pendant may swing within the cabin such that a relatively large opening in the airframe belly is required to accommodate the motion.